textproduct: Quad Cities

KEY MESSAGES

- Above normal temperatures remain forecast through the period with high temperatures peaking in the lower to mid 90s Tuesday through the end of the week. There is a 10 to 20 percent chance of heat indices over 100 Tuesday through Thursday. - Forecast remains dry through Thursday with low chances of rain Friday and Saturday.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 146 PM CDT Sun Jul 12 2026

High pressure at the surface and aloft is now in place over northeast Iowa. This position of high pressure is confidently going to be remaining there through at least Tuesday, and possibly through Thursday before significant changes occur aloft.

Ample sunshine and light winds are combining with dew point values that remain in the mid 50s north to the mid 60s ( & a few sites in the far south report near 70 ). This is leading to a pleasant summer day, with afternoon temperatures mainly in the mid 80s. Looking at temperatures yesterday, the NBM was too warm by 1-3 degrees. Today, it appears we are again over forecasting the high with the NBM as well, (forecasting 87-89 in most areas). Anyhow, this trend will need to be watched as we move forward in this warm, high pressure dominated pattern. This temperature difference led to the NBM 10th percentile verifying best yesterday.

Highs Monday with similar conditions to today, with 24 hours more modification of the high pressure are forecast in the upper 80s to low 90s, with dew points in the mid to upper 60s. This potential hot day, will likely not see heat index above 95 in the afternoon. Should the recent temperature trend of NBM over-forecasting highs, hold, highs would be limited to the mid to upper 80s.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 146 PM CDT Sun Jul 12 2026

The upper pattern will remain in place, with increasing high pressure strength through Wednesday. However, beyond Wednesday, there is some growing support for a shift to the west of the upper high, leading to a potential back door cold front as early as Wednesday night, but more likely Thursday. Given that potential, some very very low pops around 15-20% are forecast in those outer periods.

While broad support exists for highs in the lower 90s, with nearly 95% of NBM going over 90 through Wednesday, the 50th percentile remains in the 92-96F range in the period, and given our light flow beneath the high, currently under-performing temperatures, I'm inclined to cap highs at 94 through mid week, as the NBM has hot spots in the 96+ most days this week. Dew point values will increase through evapotranspiration, which is nearing seasonal peaks. However, that is the primary moisture source for this high pressure, and we will lack other typical moisture sources near the center of high pressure. The moisture levels will be an important feature in the week ahead, as it is certainly the deciding factor in heat headlines. For now, widespread mid 60s to low 70 dew points remain forecast, resulting in afternoon heat index of 93 to 100 for many days this week, but most confidently on Tuesday and Wednesday.

Beyond Wednesday, the greater spread in model data is showing up with highs as cool as the mid 80s in the lower 25% of NBM guidance late in the week, but the NBM 50% remaining in the lower to mid 90s. No matter what, we're still very much in a warm pattern through the week ahead, and heat headlines remain a possibility.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1202 PM CDT Sun Jul 12 2026

High pressure at the surface and aloft will keep winds very light over the region today through Monday. Skies will remain clear to mostly clear through the period, with only some spotty cumulus around 5-7kft this afternoon. Excellent visibility should last another night, before increasing humidity arrives Monday or Tuesday.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.